ROLE OF TG RICH RIPOPROTEINS IN ATHEROSCLEROSIS

在人单核巨噬细胞中发现了独有的载脂蛋白B48受体。该受体通过载脂蛋白B48中的一个结构域与富含甘油三酯(TG)的脂蛋白结合并相互作用。对载脂蛋白B48受体的基因序列进行了分析。免疫组织化学研究表明，抗载脂蛋白B48受体抗体和单核巨噬细胞特异性抗体共存于人动脉粥样硬化病变泡沫细胞中。免疫印迹和斑点印迹法检测到载脂蛋白B100在小肠上皮细胞中的表达。提示饮食中的极低密度脂蛋白可能在人的小肠上皮细胞中合成并转化为低密度脂蛋白，即致动脉粥样硬化的脂蛋白。一些临床研究表明，残留物(RLP胆固醇)的增加在动脉粥样硬化的形成中起着重要作用。残留物(RLP胆固醇)被认为是胰岛素抵抗状态的增加。

Unique receptor, apo B48 receptor, was identified in human monocyte-macrophages. The receptor binds and internizes triglyceride(TG)rich Lipoproteins via a domain in apo B48. The apo B48 receptor cDNA sequences were elucidated. Immunohistochemical studies indicate colocalization of anti-apo B48 receptor Ab and monocyte-macrophage specific Ab in human atherosclerotic lesion foam cells. This suggests that apo B48 receptor may contribute to foam cell formation and atherosclerosis in abnormal state with elevated TG-rich lipoproteins.Apo B100 expression in the epithelial cells of small intestine were identified by immunoblotting and dot-blotting of PCR-amplified cDNA.It suggests that dietary VLDL may be synthesized in human small intestine epithelium and converted into LDL, atherogenic lipoprotein.Some cinical studies showed that increase of remnants(RLP cholesterol), especially in postprandial state, has an important role in developimg atherosclerosis.Remnants(RLP cholesterol)were indicated to increases in the state of insulin resistance.